Method and Apparatus for Retaining Wall Boss

ABSTRACT

An apparatus ( 10 ) for leveling a layer of stone dust ( 24 ) of a foundation pad for a retaining wall, having a support assembly ( 12 ) and a scraper assembly ( 18 ). A pair of leveled guide rails ( 16 ) are utilized in parallel to support the scraper assembly such that the scraper assembly is longitudinally movable therealong. Each guide rail ( 16 ) is supported at each end by a respective support post ( 30 ) and is adjustably positionable vertically with respect to each support post such that both guide rails are levelable. The scraper assembly ( 18 ) includes a crossbar ( 42 ) with linear bearings ( 44 ) supported by respective ones of the guide rails, and also includes a depending pole ( 46 ) having a scraper blade ( 26 ) adjustably affixed at a bottom end thereof, the scraper blade being adjustable to level a bottom scraper edge ( 28 ) thereof. A method is disclosed whereby support posts ( 30 ) are positionable in pairs along the foundation pad, one post of each pair on a respective side thereof, guide rails ( 16 ) are leveled by adjusting guide rail supports ( 40 ) of each post ( 30 ), the scraper assembly ( 18 ) is positionable on the guide rails, the scraper blade is adjusted to level the bottom edge ( 28 ), and the scraper assembly is movable along the guide rails for the bottom scraper edge to level the layer of stone dust ( 24 ) along the top of the foundation pad.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional Patent Application Ser. No. 61/072,858 filed Apr. 3, 2008.

FIELD OF THE INVENTION

This relates to the field of landscaping and more particularly to masonry and retaining wall construction.

BACKGROUND OF THE INVENTION

Retaining walls are known for stabilizing soil at adjacent but different levels, and are used to eliminate sloping ground in order to maximize usable space such as for building, parking, recreational or leisure areas, or just for aesthetic appearance. Many such walls are constructed of stone, cut stone blocks or fabricated modular blocks such as of concrete, among other materials. According to the National Concrete Masonry Association (NCMA), such retaining walls that are constructed without mortar and rely on the mass of the masonry blocks and gravity for stability, are known as segmental retaining walls; see the NCMA website: http://www.ncma.org/Use/srw.html. Such segmental retaining walls require an appropriate foundation and preferably utilize anchoring for stability, with at least one layer of blocks being embedded, and it is known to provide a carefully compacted and leveled base layer or foundation such as of gravel or aggregate or a soil/aggregate mix that distributes the weight of the wall over a wide area.

One method of preparing such a base is by excavating a trench of sufficient depth for a foundation pad and also for a first level of blocks atop the foundation pad but within the trench, and then providing on the trench bottom a layer of compactible granular aggregate several inches in thickness, (six inches, for example) and compacting the aggregate. A pair of lengthy pipes or conduits are placed in parallel into the top surface of the aggregate adjacent the side walls of the trench and leveled, and a layer of stone dust about an inch or less deep is then deposited on the compacted aggregate and around the conduits to provide a level support for manual leveling of the stone dust. The conduits are placed outside of the active area of the base, that is, to both sides of the eventual location of the first layer of masonry blocks. In manual leveling, a scraper and a level are then used together manually, supported by the top surfaces of the conduit pair from one end of the trench to the other, to assure that the top surface of the stone dust is even and level. After a first leveling process, the conduits are temporarily removed from the stone dust and the stone dust is then compacted, preferably by a vibrating plate, usually with several passes over the dust. Then the conduits are replaced in the stone dust and additional stone dust applied and leveled as before; the conduits are then removed. The masonry blocks then are then placed onto the active area of the prepared level pad for construction of the wall.

It is desired to provide an efficient apparatus and method for precision leveling of a retaining wall foundation pad.

BRIEF SUMMARY OF THE INVENTION

Briefly, the present invention is an apparatus and a method for precisely leveling a foundation pad for a retaining wall in an economical, labor- and time-saving manner. The apparatus includes a pair of legs or posts, the posts of each pair positioned on respective sides of the foundation pad, which is most commonly disposed along the bottom of a trench, at first and second positions along the length of the foundation pad, and which are then preferably firmly anchored in position. The two posts of each pair may be joined at their top ends such as by a crossbar, thereby defining an end brace. A pair of parallel guide rails are positioned horizontally between the end braces and affixed to the posts along respective sides of the foundation pad. The guide rails are removably and adjustably affixed to the end brace posts at each rail end, and the guide rails are leveled between the pair of end braces and with each other at a selected height above ground level to each side of the trench, i.e., in a horizontal plane, keeping in mind that the ground levels to each side of the trench or even between the end braces on one or both sides are most commonly different. Altogether, the pairs of posts, or end braces, and the pair of guide rails, can be said to comprise a support frame assembly

A scraper assembly is hung from the guide rails to depend into the trench for a scraper blade at the bottom of the assembly to just engage the top of the stone dust of the foundation pad; the scraper blade preferably is adjustably positionable with respect to the scraper assembly to level the scraper blade such as through use of a level. By use of linear bearings, such as square bearings where the rails are of square cross-section, the scraper assembly, and therefore the now-leveled scraper blade, is carefully, incrementally and easily moved continuously along the rails for the scraper blade to level the stone dust along the length of the trench between the first and second end brace positions, thereby scraping a level surface onto the stone dust layer, whereafter the scraper assembly is removed from the rails. A vibrating plate may then be used to compact the leveled stone dust layer; another layer of stone dust is preferably then applied and leveled as before. Also, preferably, the end braces are of such height that the vibrating plate apparatus will pass under them.

Also, preferably, the scraper assembly is re-positionable from side to side between the rails, such as along a transverse rail securing the scraper assembly to the parallel rails, from generally being positioned along one side of the trench after a leveling pass, to the other side for a second leveling pass, for use with a relatively wide active area for the masonry blocks by leveling adjacent side portions of the stone dust layer. The rails can then be removed from the end braces, and the first end brace can then be repositioned at a third position, essentially “leap frogging” the second end brace at the second position; the rails are then re-positioned between the second end brace and the newly re-positioned first end brace and again leveled, and the stone dust leveling process repeated, and so on, thus accommodating preparation of a long foundation pad.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the presently preferred embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain the features of the invention. In the drawings:

FIG. 1 is an isometric view of a support frame assembly of the present invention including the end braces and the guide rails astride a trench containing a foundation pad;

FIG. 2 is an end view of the present invention showing the scraper assembly depending from the guide rails of the assembly of FIG. 1;

FIG. 3 is an isometric view of an end brace of FIGS. 1 and 2;

FIG. 4 is an enlarged part cross-sectional view of a post of the support frame assembly of FIG. 1 and an adjustable clamp assembly with a guide rail support;

FIG. 5 is a view of exemplary guide rails wherein (A) is rectangular in cross-section, (B) is diamond-shaped in cross-section, and (C) is tubular;

FIG. 6 is an isometric view of the scraper assembly of FIG. 2, with arrows indicating directions of vertical and horizontal positional adjustments for the scraper blade;

FIG. 7 is an end view of a second embodiment of the invention, similar to FIG. 2, showing another type of scraper assembly and support frame assembly with respect to a trench;

FIGS. 8 and 9 are additional embodiments of scraper subassemblies;

FIG. 10 illustrates another embodiment of adjustable-height post and crossbar of an end brace;

FIG. 11 is another embodiment of a support frame assembly in isometric view astride a trench;

FIGS. 12 and 13 are enlarged assembled and exploded views of a guide rail support adjustably securable to a post of an end brace;

FIG. 14 is a view of the top of an end brace post of FIGS. 12 and 13 illustrating the slot with toothed rack utilized in the securing arrangement of FIGS. 12 and 13; and

FIG. 15 is an additional embodiment of a scraper assembly including a laser leveling device affixed thereto for precision leveling of the scraper blade.

DETAILED DESCRIPTION OF THE INVENTION

In the drawings, like numerals indicate like elements throughout. Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The term “foundation pad” refers to a sublayer of gravel and a top layer of stone dust to serve as a foundation for a retaining wall. The term “trench” refers to a trench dug into soil at a site for a retaining wall to a depth to contain the foundation pad and at least a first layer of stone, cut stone blocks or fabricated modular blocks such as of concrete, and the like, for constructing the retaining wall. The terminology includes the words specifically mentioned, derivatives thereof and words of similar import. The embodiments illustrated below are not intended to be exhaustive or to limit the invention to the precise form disclosed. These embodiments are chosen and described to best explain the principle of the invention and its application and practical use and to enable others skilled in the art to best utilize the invention.

FIGS. 1 and 2 show a first embodiment of the retaining wall boss 10 of the present invention. Boss 10 includes a support frame assembly 12 comprising a pair of first and second end braces 14 supporting a pair of guide rails 16, and a scraper assembly 18 depending from guide rails 16, for use in relationship to a foundation pad 20 shown disposed along the bottom of a trench 22 and having a compacted layer of gravel 24 covered by a level of stone dust 26 in need of leveling. Generally, guide rails are adjustably secured to the end braces to be capable of being made level longitudinally and with each other. The scraper assembly 18 is supported by and movable horizontally along the pair of guide rails 16 for the bottom edge 28 of the scraper blade 26 to smooth and level the stone dust layer 24; preferably, the scraper blade 26 is adjustably secured to the scraper assembly 18 in order for its bottom edge to be capable of being made level. The length of guide rails may be about eight or ten feet in length and the first and second pairs of end posts (or end braces) may be positioned about seven or nine feet apart, for leveling a first length of foundation pad such as about six to eight feet.

Referring now to FIGS. 2 to 4, regarding support frame assembly 12, each end brace 14 comprises a pair of posts 30 joined at top portions thereof by a crossbar 32. Each post includes a base 34 adapted to anchor the post to the ground in a stable vertical orientation. Each post base 34 should be heavy and widened and include one or more anchor pegs to penetrate the soil, all to provide stable support resistant of any movement along the soil or being tilted. Each post 30 is also adapted to permit vertical adjustment of a clamp assembly 38, such as by a vertical rail adjustment guide or slot 36, where the clamp assembly 38 includes a forged steel clamp draw down, an interior bushing 39, a washer and a guide rail rest or support 40 having a set bolt 41. Each adjustment guide or slot 36 extends from the outer or guide rail remote surface of the post 30 to the inner or guide rail adjacent surface thereof. The clamp assemblies 38 must be sufficiently robust to support the guide rails 16 and scraper assembly 18 over many adjustment cycles.

In FIG. 5, several embodiments of a guide rail 16 are shown. Embodiment (A) is rectangular; embodiment (B) is diamond shaped; and embodiment (C) is tubular. Each guide rail 16 must be resistant to sagging under the weight of the scraper assembly 18, and must permit the scraper assembly to be moved longitudinally therealong. An exemplary material is aluminum box or tube.

Scraper assembly 18 will now be described in detail with reference to FIG. 6. Crossbar 42 extends transversely between the pair of guide rails 16 (FIG. 2), and preferably integrally formed at ends thereof are guide rail linear bearings 44 which are operatively associated with the guide rails. One example of a linear bearing having a square rail opening is Product No. MSC #: 35419746, Part #PST16-48 sold by MSC Industrial Supply Co., Inc. of Melville, N.Y. A vertical pole 46 depends from crossbar 42 and scraper blade 26 is adjustably secured at the bottom of vertical pole 46. As shown, guide rail bearings 44 are shown as sleeves that provide inverted grooves 48 that are disposed over and atop the guide rails and are complementary therewith; again, as shown, grooves 48 are U-shaped to correspond with rectangular guide rails 16 depicted in FIGS. 1 and 2 and guide rail 16(A) of FIG. 5, and in a manner permitting longitudinal movement with respect to the guide rails. Preferably, vertical pole 46 is disposed within a vertical sleeve 50 that is affixed to crossbar 42 by a horizontal sleeve 52, such that vertical pole 46 is vertically adjustable in position and such that the vertical pole is also horizontally adjustable in position by corresponding adjustment of the horizontal sleeve 52 with respect to the crossbar 42 both through the use of clamp assemblies 54,56.

Scraper blade 26 is adjustably secured to a horizontal beam 58 affixed to the bottom of vertical pole 46 by a pair of clamp assemblies 60, for example. The pair of clamp assemblies permit the scraper blade to be angularly adjustable to achieve leveling of the scraper bottom edge 28. Both clamp assemblies are shown to be disposed through arcuate slots 62 of scraper blade 26 for this purpose, although one of the clamp assemblies could simply be fixed in relative position, allowing the other to be relatively moved through its respective arcuate slot 62. Clamp assemblies 54,56, 60 may be set bolts.

Another embodiment of retaining wall boss 110 is illustrated in FIGS. 7 and 8, including a support frame assembly 112 and a scraper assembly 118, shown in position with respect to a trench 20. Support frame assembly 112 is shown to comprise four posts 130 (two of which are hidden) in two pairs each post independent of and unjoined to the other post of its pair and having a base 134 utilizing an anchor peg 135 driven as a stake through an aperture therethrough and into the ground. Guide rails 116 are supported by clamp assemblies 138 that are shown to include annular bands that are tightenable about and to respective posts 130 when the desired height of the guide rail has been determined during leveling.

Best shown in FIG. 8, scraper assembly 118 includes a crossbar 142 with guide rail bearings 144, with the bearings including a transverse sleeve through which a respective end portion of crossbar 142 extends, permitting transverse or horizontal movement of the scraper assembly with respect to the foundation pad. This permits the scraper assembly to make two passes parallel along the foundation pad, each leveling a respective side portion of the layer of stone dust. A pair of angled vertical posts 146 depend from crossbar 142 each joining a horizontal bar 158 at their bottom ends. A pair of upstanding projections 161 rise from scraper blade 126 spaced horizontally from each other, both including vertical slots 162 associated with respective clamp assemblies 160 of horizontal bar 158 to permit vertical adjustment of either end of the scraper 126 for leveling thereof.

Another embodiment of scraper assembly 218 is illustrated in FIG. 9, wherein a crossbar 242 extends through a horizontal sleeve 252 with a pair of poles depending therefrom having scraper 226 affixed to bottoms thereof, preferably by an adjustable joint (not shown). Again, the scraper assembly is horizontally movable between the guide rails. Crossbar 242 is shown to have guide rail bearings 248 complementary to tubular guide rails of the type 16C shown in FIG. 5.

FIG. 10 depicts an alternate embodiment of vertical post 230 for the support frame assembly. Post 230 includes a telescoping inner post 231 therewithin having adjustable height using a clamp assembly 238. A guide rail support 240 is positioned atop telescoping inner post 231 to support a guide rail 216.

Another embodiment of support frame assembly 312 is illustrated in FIG. 11, wherein a pair of end braces 314 each comprise a unitary structure with two post sections 330 joined by an integral arcuate top section or bight 332. Guide rails 316 are each adjustably joined to respective post sections 330 at ends thereof by a clamp assembly 338 that is adjustably positionable through a slot 336 extending longitudinally along and through an associated post section 330. A manual level 390 is shown being used to assure leveling of the guide rails 316.

An embodiment of clamp assembly 438 is shown in FIGS. 12 to 14, for use with an end brace 414 (FIG. 14) having posts 430. Each post 430 includes a guide rail adjustment guide or slot 436 as in post 30 of FIG. 1, and additionally includes a pair of linear gear drives 470, each along a side of the slot on the inwardly facing and outwardly facing surfaces of post 430. Clamp assembly 438 includes a companion geared adjusting sleeve 439 having inner and outer gear wheels 472 a,472 b, preferably all a one-piece, integral unit extending through a respective slot 436 of a post 430 and concluding in an adjusting handle 474 outwardly of outer gear wheel 472 b. A bolt 476 extends from guide rail support 440 (having a set bolt 441 to tighten against a guide rail) to a threaded end 476 a and is extended through a spacer or washer 478, then through and beyond geared sleeve 439 for its threaded end to protrude beyond the outer surface of post 430. Finally, a base clamp 480 and a clamp member such as, preferably, a camming clamp/lever 482 with nut 484 is threaded tightly onto the threaded end of bolt 476. Camming clamp/lever 482 is pivotable about the nut 484 to cam against and press base clamp 480 against the outer post surface, thus cinching the entire clamp assembly 438 to the post 430 when the geared adjusting sleeve 439 has been moved to its desired position by manual rotation of adjusting handle 474.

FIG. 15 is illustrative of a scraper assembly 518 having a laser receiver 592 mounted on the top of a grade pole 594 adjustably affixed to the scraper assembly 518. The grade pole bottom end is supported by a grade pole rest 596 affixed to the scraper blade 526, and extends vertically upwardly through a grade pole bracket 598 with set screw. Otherwise, the scraper assembly 518 is similar to that shown in FIGS. 2 and 6. Such a laser receiver is utilized with a rotary laser that emits a laser beam, and the grade pole is vertically adjustable to achieve the desired height for leveling, at which position the grade pole is locked to the scraper assembly; the laser system can also be used to achieve a certain vertical distance with reference to an onsite benchmark, such as the desired level of the top finish of the eventual wall. Such laser products are sold by CST Berger, division of The Stanley Works, having a website: www.cstberger.com.

The method of the present invention comprises the steps of: positioning and anchoring the two pairs of posts of the support frame assembly spaced apart along the sides of the foundation pad, or trench; positioning the guide rails in the guide rail supports of the posts and leveling them by adjusting the height of the guide rail supports; positioning the scraper assembly on the guide rails and selecting the desired height of the scraper blade; leveling the bottom edge of the scraper blade; and leveling the stone dust with the bottom scraper edge by incrementally moving the scraper assembly along the guide rails. First and second passes along the same length of foundation pad may be accomplished by adjusting the position of the scraper assembly from a first transverse position between the guide rails to a second transverse position. Subsequently, for an elongated foundation pad, the scraper assembly may be removed from the guide rails and the original end pair of posts (or end brace) may then be moved past the second pair of posts and repositioned and anchored, the guide rails repositioned in the guide rails supports and leveled, and the scraper assembly repositioned onto the guide rails to level a second length of foundation pad, and so on.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. 

1. An apparatus for leveling a layer of stone dust of a retaining wall foundation pad, comprising: a support frame assembly having first and second pairs of posts each of which has a guide rail support adjustably affixed thereto to be movable vertically therealong, and a pair of guide rails operatively associated with the guide rail supports of first posts and second posts of each of the first and second pairs of posts, the guide rails being generally parallel and positionable a selected distance apart one on each side of the foundation pad; and a scraper assembly having a crossbar supportable by the pair of guide rails and extending transversely therebetween in a manner permitting longitudinal adjustment movement of the scraper assembly with respect to the guide rails, the scraper assembly including at least one depending pole concluding in a scraper blade at the bottom thereof, the scraper blade having a bottom scraper edge for engagement with the layer of stone dust of the foundation pad, and the scraper blade being vertically adjustably positionable with respect to the crossbar and also angularly adjustable with respect to the scraper assembly for leveling of the bottom scraper edge.
 2. The apparatus of claim 1, wherein the posts of each pair thereof are joined together by a crossbar at least affixable adjacent top ends of the posts, thereby defining an end brace.
 3. The apparatus of claim 1, wherein the posts of each pair are joined at top ends thereof by an arcuate bight section to define an end brace.
 4. The apparatus of claim 1, wherein each guide rail has a rectangular cross-section selected from the group of shapes consisting of: rectangular, diamond-shaped and tubular.
 5. The apparatus of claim 1, wherein each guide rail support of each post includes a set bolt to be tightenable against a guide rail positioned therein.
 6. The apparatus of claim 1, wherein each guide rail support is positioned on a surface of a respective post of the first pair of posts facing a corresponding post of the second pair of posts, and the clamp assembly is longitudinally aligned with the guide rail.
 7. The apparatus of claim 1, wherein each post includes a telescoping inner pole vertically adjustable with respect to an outer sleeve of the post, and the guide rail support is positioned atop the telescoping inner pole.
 8. The apparatus of claim 1, wherein each post includes a base at its bottom end for securing the post in its desired position stabilized against tipping or horizontal movement, wherein each base includes at least one anchor peg to penetrate ground on which the post is positioned.
 9. The apparatus of claim 1, wherein each post includes a vertical slot therethrough, and wherein the guide rail support of each post includes a clamp assembly having a sleeve extending through the vertical slot from an outer or guide rail remote post surface to an inner or guide rail adjacent post surface, and wherein the clamp assembly is lockably affixable to its respective post, whereby the clamp assembly is locatable and lockable at any vertical location within a vertical range permitted by the vertical slot.
 10. The apparatus of claim 9, wherein the clamp assembly includes a geared adjusting sleeve with outer and inner gear wheels, and the respect post includes a pair of linear gears mounted to the outer and inner post surfaces adjacent the slot therethrough that are cooperable with the outer and inner gear wheels for incremental vertical movement of the clamp assembly with respect to the respective post, and wherein the geared adjusting sleeve includes an adjusting handle at an outer end thereof spaced outwardly from the outer gear wheel facilitating the vertical adjustment of the clamp assembly.
 11. The apparatus of claim 10, wherein the clamp assembly further includes a bolt extending horizontally from a guide rail support of the respective post to pass through the geared adjusting sleeve for a bolt end to protrude beyond the outermost extent of the geared adjusting sleeve for a clamp member to be secured thereonto, wherein the bolt end is threaded and the clamp member includes a nut that is correspondingly threaded, and wherein the clamp assembly further includes a base clamp that is firmly pressed against the outer post surface upon actuation of the clamp member, to lock the clamp assembly and the guide rail support in position.
 12. The apparatus of claim 1, wherein the crossbar of the scraper assembly includes adjacent each end a guide rail bearing adapted to be supported by and movable along a respective one of the guide rails, and wherein the crossbar is transversely movable with respect to the guide rail bearings.
 13. The apparatus of claim 1, wherein the at least one depending pole of the scraper assembly is adjustable horizontally with respect to the crossbar thereof.
 14. The apparatus of claim 1, wherein the depending pole of the scraper assembly is adjustable vertically with respect to the crossbar thereof.
 15. The apparatus of claim 1, wherein the scraper blade is secured to a horizontal beam at the bottom end of the depending pole of the scraper assembly.
 16. The apparatus of claim 15, wherein the scraper blade is secured to the horizontal beam at two spaced apart locations along the beam by clamp members, wherein at least one of the clamp members extends through an arcuate slot to pivot around the other of the clamp members, for angular movement during leveling adjustment of the bottom scraper edge.
 17. The apparatus of claim 1, wherein the scraper assembly includes two depending poles spaced apart along the crossbar and joined together by a horizontal beam at least proximate their bottom ends.
 18. The apparatus of claim 17, wherein the scraper blade includes a pair of upstanding poles spaced horizontally apart and each permitting vertical adjustments of respective associated ends of the scraper blade with respect to the horizontal beam, for leveling of the bottom scraper edge.
 19. The apparatus of claim 1, wherein the scraper assembly includes a removably attachable and vertically positionable grade pole for a laser receiver, for leveling.
 20. A scraper assembly for use in conjunction with a pair of horizontal parallel guide rails, for leveling a layer of stone dust of a foundation pad, comprising: a crossbar supportable by the pair of guide rails and extending transversely therebetween in a manner permitting longitudinal adjustment movement of the scraper assembly with respect to the guide rails, the scraper assembly including at least one depending pole concluding in a scraper blade at the bottom thereof, the scraper blade having a bottom scraper edge for engagement with the layer of stone dust of the foundation pad, and the scraper blade being vertically adjustably positionable with respect to the crossbar and also angularly adjustable with respect to the scraper assembly for leveling of the bottom scraper edge.
 21. A method for leveling a layer of stone dust of a foundation pad for a retaining wall, comprising the steps of: providing a support assembly including a pair of guide rails each supported adjacent ends thereof by respective support posts positioned alongside the foundation pad and so positioned as to orient the guide rails to be parallel to the foundation pad and each other; providing a scraper assembly including a crossbar having guide rail bearings adjacent respective ends thereof each associated with a respective guide rail, and including at least one depending pole having a scraper blade adjustably affixed to a bottom end thereof, leveling the pair of guide rails by vertically adjusting guide rail supports with respect to the associated posts; leveling a bottom blade edge and lowering the bottom blade edge into leveling engagement with the layer of stone dust of the foundation pad; and longitudinally moving the scraper blade along the pair of guide rails thereby moving the bottom scraper blade along the layer of stone dust, leveling same.
 22. The method of claim 21, further comprising the step of horizontally adjusting the location of the at least one depending pole with respect to the pair of guide rails.
 23. The method of claim 22, by moving the scraper blade in a first pass leveling a first side portion of the layer of stone dust when the scraper assembly is in a first horizontal position between the guide rails, and then moving the scraper assembly to a second horizontal position between the guide rails and moving the scraper blade in a second pass leveling a second side portion of the layer of stone dust.
 24. The method of claim 21, further comprising the steps of: removing the scraper assembly from the guide rails after leveling a first length of the layer of stone dust of the foundation pad; removing the guide rails from the support posts; moving a first pair of support posts from an original location, past the second pair of support posts and positioning the first pair of support posts in a subsequent location; replacing and re-leveling the guide rails; replacing the scraper assembly onto the guide rails; and leveling a subsequent length of the layer of stone dust of the foundation pad. 